This post describes a dive at the “Pipeline” site, Nelson Bay, in late February. It’s not science, and not a dramatic tale, just 90 minutes or so of octopus behavior – one brief period in their complicated lives.

Dive conditions were good. I headed a little to the north-east, exploring. I came across a cluster of octopuses. The first had a good den with a bottle nearby (as they often do), and was very watchful. He’ll be “Bottle Octopus,” or O1.

He was arranged with shells around, peering out, a...